[typescript-eslint] Rethinking generic type parameter naming convention

[tetsuharuohzeki]

Motivation

Currently, we define the generic type name convention to both forms:

1. T, E, or other short form.
2. T or TBar or other T-prefixed form.

On the other hands, the default config of typescript-eslint only allows the later form.

I think the later form is more expressive and improves a readability. So I'd like to sort to it.

Related Issue

• https://github.com/cats-oss/eslint-config-abema/issues/69

[tetsuharuohzeki]

C

I'm not sure about the detail of history of this kind of conventions for C#, I seem C# has these rules:

• Generic Type Parameters - C# Programming Guide | Microsoft Docs
• Framework Design Guidelines on Names of Generic Type Parameters – Brad Abrams
  • Internet Archive

[tetsuharuohzeki]

TypeScript

• https://github.com/Microsoft/TypeScript/wiki/Coding-guidelines
  • This is NOT a prescriptive guideline for the TypeScript community.
  • But I think this is nice example to think about this issue.
• By typescript compiler code base, their actual codes convention is similar to C#, I seem.

[tetsuharuohzeki]

Java

• Generic Types (The Java™ Tutorials > Learning the Java Language > Generics (Updated))

Scala

• https://docs.scala-lang.org/style/naming-conventions.html#type_parameters_generics

Kotlin

I could not find any conventions, but I found the discussion: https://discuss.kotlinlang.org/t/naming-convention-for-type-parameters/1546

[tetsuharuohzeki]

Rust

https://github.com/rust-lang/rfcs/blob/master/text/0430-finalizing-naming-conventions.md

[tetsuharuohzeki]

Google C++ Style Guide

https://google.github.io/styleguide/cppguide.html#General_Naming_Rules

Template parameters should follow the naming style for their category: type template parameters should follow the rules for type names, and non-type template parameters should follow the rules for variable names.

[tetsuharuohzeki]

Some thought

• C#/TypeScript style is most expressive and I seem it's nice for application code.
  • It's a bit verbose style for library code, but I follow this style because the main target of this project is just application.
• I feel Java/Scala/Kotlin/Rust style is short and popular style in this industry.
  • But I don't seem it's always readable.
• I don't think Google C++ Style Guide is nice example for our TypeScript naming convention...
• Of course, we should check this kind of coding problem in the coding review phase, but I also think we can check it automatically and it avoid the tired bike-shedding.